fn main() {
    // 填空
    let b = false;

    let _v = match b {
        true => 1,
        // 发散函数也可以用于 `match` 表达式，用于替代任何类型的值
        false => {
            println!("Success!");
            todo!()
            // panic!("we have no value for `false`, but we can panic")
        }
    };

    println!("Exercise Failed if printing out this line!");
}
